A pulmonary giant cell carcinoma in a dog

A case of a large cell anaplastic carcinoma of the giant cell type in the lungs of a 5 year-old crossbred male Labrador is discussed. The dog was weak, depressed, febrile and markedly dyspnoeic. An intermittent moist cough and auscultable crackling rales were evident. Radiographic examination was indicative of pneumonia and pulmonic neoplasia. The dog died 36 hours after admission despite antibiotic and supportive therapy. At autopsy, the neoplasm appeared as numerous firm greyish-white nodules of varying size throughout all the lung lobes whilst in the right intermediate and diaphragmatic lobes the neoplasm was completely confluent. The microscopic features included: intra-alveolar composites of cells exhibiting considerable nuclear and cytoplasmic pleomorphism; the presence of numerous giant cells scattered throughout the tumour; the occurrence of tumour emboli within both venous and lymphatic vessels; and, metastatic foci in the bronchial and mediastinal lymph nodes. These features were considered to reflect a high degree of malignancy. Comparative and aetiological aspects of bronchogenic carcinomas in man and the dog are discussed.